Digital BW, The Print

----- Original Message -----
From: "hsitz" <hsitz@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Friday, March 29, 2002 1:42 PM
Subject: Re: [Digital BW] Is dynamic range more important than density
range?


> --- In DigitalBlackandWhiteThePrint@y..., "Martin Wesley"
> <mwesley250@e...> wrote:
> > Herb,
> >
> > What you say makes sense only if there are a finite number of
> tones. In a
> > full range continuous tone silver print there are no steps between
> min and
> > max density but an infinite number of tones. If you can achieve a
> continuous
> > tone print from a digital source the same would apply there.
>
>
> Martin -- Well, I'd say that what I say makes sense whether there are
> a finite number of tones or an infinite number that are available in
> a silver printing process.  But that if you think there are an
> infinite number of tones available to an analog process then you
> might just think it's silly to try to compare the 'dynamic range'
> (using Austin's meaning) of the two systems.  So you're left with
> comparing density ranges.

Herb,

That pretty much sums it up form my point of view.
>
> By the way, I also think it doesn't make much sense to think of there
> being an infinite number of tones available in a silver process (even
> if there are in reality, which seems dubious to me).  Even assuming
> that there were an infinite subtlety of tones in some silver print,
> our eyes are a limiting factor there; there's no way we can
> distinguish adjacent tone steps from another after a certain subtlety
> of step size is reached.  If the dynamic range of digital printers
> increases to reach the ability to print tone steps more subtly than
> we can differentiate between them, then for all practical purposes
> the dynamic range of a digital print will be as great as that of a
> silver print.

If the printing medium, silver, digital inkjet or whatever, successfully
fools our eye into thinking it is continuous tone then does Austin's
definition of dynamic range apply, or if it applies, is it meaningful?  Can
we at least agree that our goal is to have a print that appears to be
continuous even though it may not be at some microscopic or quantum level?
>
> Our sensory perception has also shown up as a limiting factor in
> digitization of music, where even if the analog recordings had
> infinite gradations of tone, the (then more limited) subtlety of CD
> recordings captures gradations of tone beyond our ability to
> distinguish them.  (By the way, I think it turns out that audio CD's
> actually have greater dynamic range (i.e., more subtlety of tone)
> than what you can get in an analog process, which kind of goes
> against there being an infinite subtlety of tone possible in silver
> prints.)

I agree and was never able to hear the subtle distinction claimed by the pro
analog audio supporters. In theory it would have been nice to have sampled
at a higher rate but in practice no one could reliably tell the difference.
The new DVD audio standards seem to be excessive in the other direction.
Which leads to the point that once you have convinced the eye or ear that
they are receiving a continuous tone signal, how important is DR as Austin
defines it? Below that point its value is obvious but above it, as the noise
factor goes toward zero, it seems less and less meaningful in comparing
systems.
>
> Similarly with digital projectors (you know, what businessmen use for
> presentations) and CRT projectors, which are analog.  A digital
> projector that has a resolution of 800 x 600 pixels will display an
> image that looks pixelated and digital if you look at it from a few
> feet away.  But if you move back to several times the width of the
> image you can no longer make out the pixel structure.  For all
> practical purposes, it will then appear seamless; we can no longer
> distinguish between adjacent pixels of the same color.  I know this
> example doesn't have to do with dynamic range of images, but it's
> related, I think.

I think it is an appropriate example and illustrates that my claim of
infinite tones may be irrelevant once you have reached a number of tones
where the eye cannot distinguish between two adjacent tones.

Martin